Communicating Science

to the Public

Paul A. Offit, MD

The Children’s Hospital of Philadelphia

The University of Pennsylvania School of Medicine

MMR-Autism: Scientific Studies I

Taylor, B, et al. Lancet 1999;351:2026-29

Dales L, et al. JAMA 2001;285:1183-85

Kaye JA, et al. Brit Med J 2001;322:460-3

Madsen KM, et al. N Engl J Med 2002;347:1477-82

Peltola H, et al. Lancet 1998;351:1327-8.

MMR-Autism: Scientific Studies II

Makela A, et al. Pediatrics 2002;110:957-63

DeStefano R, et al. Pediatrics 2004;113:259-66

Farrington CP, et al. Vaccine 2001;19:3632-5

Fombonne E, et al. Pediatrics 2001;108:e58

Taylor, B, et al. British Med J 2002;324:393-6

Thimerosal-Autism: Scientific studies

Hviid A, et al. JAMA 2003;290:1763-66

Andrews N, et al. Pediatrics 2004;114:584-91

Herron J. Pediatrics 2004;114:577-83

Verstraeten T, et al. Pediatrics 2003;112:1039-48

Barbaresi W, et al. Arc Ped Ado Med 2005;159:37-44

Schecter R, et al. Arch Gen Psychiatry 2008;65:19-24

Defeating Epidemiology

The fallacy of balance

Epidemiological studies cannot detect rare events

“Vaccines might cause autism in a

small group of genetically

susceptible individuals.”

Power of epidemiological studies

Paralysis (GBS) and swine flu vaccine

Intestinal blockage and rotavirus vaccine

Low platelets and measles vaccine

Omnibus Autism Proceeding

Epidemiological studies don’t prove anything

Epidemiological studies and proof

Flying like Superman

WMD in Iraq

Cigarette smoking and lung cancer

Anecdote trumps epidemiology

The power of box “a” Disease No disease

Vaccine a b

No vaccine c d

Risk in “vaccine” group = a /a + b Risk in “no vaccine” group c/ c + d

Cultural Biases

The media defends the weak against the powerful

Players in vaccine-autism controversy

If you care about children with autism, you support the notion that vaccines are the cause. Lawyers, politicians, fringe scientists, and journalists care.

Doctors, public health officials, mainstream scientists and pharmaceutical companies don’t care.

Players in autism controversy are miscast

Doctors and scientists who oppose notion that vaccines cause autism are standing up for the little guy

Those who claim that vaccines cause autism hurt children by providing false hope, proffering dangerous therapies, and diverting limited resources

The media loves mavericks

“While Galileo was a rebel, not all

rebels are Galileo.”

Michael Fitzpatrick

The media falls into the single-study trap

Wakefield, A.J., et al. Lancet 351: 637-641, 1998.

The media doesn’t understand science

What Science Isn’t

Science isn’t scientists or scientific bodies or accumulated knowledge

Science is a way of thinking about or approaching a problem

Although scientists get it wrong all the time, science is enormously self-correcting; but fluidity of science can be disconcerting

Explaining cause and effect

The Lay of the Land

Belief Percent of population

Astrology 50

ESP 46

Witches 19

Aliens already landed 22

Commune with dead 42

Ghosts 35

Conflicts of interest

Ad hominem attacks

If you don’t have the data, discredit the

messenger

Appeal to personal considerations rather

than logic or reason

CDC, AAP, individuals under fire

Easy appeal to toxic, environmental hell

Easy to scare people;harder to unscare them

Poor understanding of risk

Scared of pandemic flu, but not epidemic flu; of radon, but not strokes and heart attacks; of dioxin, but not French fries; of plane travel, but not car travel; of MMR vaccine, but not measles; and of thimerosal-containing influenza vaccine, but not influenza.